Several types of power supply circuits exist that can be used to receive alternating current (AC) power from AC power sources and to supply a small amount of power at direct current (DC) voltage levels to individual integrated circuits. A typical integrated circuit to be powered may, for example, require only about ten milliamperes of supply current at a low supply voltage of 3.3 volts. One particularly advantageous non-isolated AC-to-DC converter power supply circuit usable to receive AC power from an AC source and to output a small amount of power at a DC voltage level is set forth in: 1) U.S. patent application Ser. No. 13/569,458, entitled “High-Efficiency, Low-Power Supply Circuit”, filed Aug. 8, 2012, by Leonid A. Neyman, now published as US2014/0043878, and 2) U.S. patent application Ser. No. 14/152,989, entitled “Non-Isolated AC-to-DC Converter Having A Low Charging Current Initial Power Up Mode”, filed Jan. 10, 2014, by Leonid A Neyman, now published as US2014/0126258.